Wall scratcher



Jan. 17, 1961 Filed Dec. 11. 1956 2 Sheets-Sheet 1 J7 Jam/#27155 152W: 75 INVENTOR.

I k i L. A. HENE WALL SCRATCHER Jan. 17, 1961 2 Sheets-Sheet 2 FiledDec. 11. 1956 Zz/mmerfl AQW:

INVENTOR.

United States Patent WALL SCRATCHER Lennart A. Hene, South Gate, Califi,assignor to Borg- Warner Corporation, Chicago, Ill., a corporation ofIllinois Filed Dec. 11, 1956, Ser. No. 627,613

20 Claims. (Cl. 166-173) The present invention relates to wallscratchers, and more particularly to a wall scratcher having improvedand novel scratcher fingers and means for securing said fingers on thesupporting collar.

In the treatment of oil wells, it frequently becomes necessary and/ordesirable to scratch the surface of the borehole to remove mud cake thatis deposited thereon during the circulation of drilling mud down throughthe drill pipe or casing and up through the annular space between thecasing and the borehole. Such scratching, or removing of the cake, isparticularly desirable prior to cementing a casing or liner string inplace in the borehole.

'Heretofore, scratchers have been provided for this purpose, suchscratchers generally comprising a support ing collar adapted to encirclea string of tubing or pipe with a plurality of scratcher fingersradiating from the collar for engagement with the surrounding bore holefor scratching the surface of the latter.

A principal object of the present invention is to provide an improvedscratcher of the aforesaid general type having a sectional collaradapted to encircle a tube or pipe and having improved means forsupporting on the collar a plurality of flexible scratcher fingers.

- Another object is to provide a scratcher device of this type havingimproved scratcher fingers formed of wire bundles enclosed and encasedby a coiled spring with the ends of the wires of the bundles projectingfrom the coiled springs, thus providing a multiplicity of scratcherelements on each scratching finger, somewhat in the nature of a crowsfoot.

A further object is to provide means for securing flexible scratcherfingers on a supporting collar or collar section, including a generallyT-shaped element adapted to lie against the outer periphery of thecollar with a flexible scratcher element folded about the stem of the Tso as to be substantially U-shaped, with the sides of the scratcherelement extending along'the T-stem into over-' lying engagement with theT-head, whereby the T-head will cause the arms of the scratcher elementto flex outwardly with respect to the collar for scratching engagementwith the walls of a bore hole.

Still another object is to provide a structure in accordance with thelast preceding object wherein the collar is lanced or slit to receivethe T-member and the' U- shaped scratcher element with alternate ribsbetween the lances respectively overlying and underlying the T-stem andthe contiguous portion of the scratcher element, whereby certain ribsmay be indented to securely clamp the T-member. In addition, a scratchermember-securing tab is also preferably struck or stamped out of thecollar and bent over the base of the U-shaped scratcher to securelyretain the same in place and against displacepended claims.

In the drawings:

Figure l is a view showing the wall scratcher hereof in top plan, asmounted upon a section of pipe or casing which is shown in section;

Figure 2 is a view in side elevation showing the wall scratcher mountedupon a section of pipe or casing and showing the improvedscratcher-finger mounting means hereof;

Figure 3 is an enlarged view in section as taken on the line 3-3 ofFigure 2;

Figure 4 is a fragmentary view in section as taken on the line 4-4 ofFigure 3; and

Figure 5 is a view in perspective of the T-shaped member utilized in thescratcher finger securing means.

Like reference characters in the several figures of the drawings and inthe following detailed description designate corresponding parts.

Referring to Figures 1 and 2 of the drawings, the wall scratcher hereofcomprises a cylindrical supporting collar 1, which preferably composedof a pair of similar halfsections 2 and 3. The half-sections 2 and 3 arepreferably detachably interconnected so that the collar may be easilymounted upon a pipe or casing generally designated 4. In theillustrative embodiment, the collar sections 2 and 3 are shown as havingcooperatively interlocked overlapping flanges on their respective ends,although other specific means may be availed of for interconnecting thehalf-sections together as may be desired.

In a plurality of circumferentially-spaced positions about the collar 1,it is lanced or slit so as to provide a plurality of alternateoutstanding ribs 5, which are spaced outwardly with relation to asuitable number of intervening ribs 6, thus providing a channel orsocket.

Interposed in the space between the ribs 5 and 6 is a generally T-shapedelement 7, having stem 8, lying between ribs 5 and 6, and a head 9,which serves a function hereinafter to be described in detail.

At the junction of the T-stem 8 with the T-head 9, the upper surface ofthe T-element 7, is provided with a generally rectangular projection 10,which provides a shoulder 11, engageable with one of the ribs 5, so asto properly position the T-shaped element 7 between the ribs 5 and 6when the stem 8 is inserted therebetween.

Also disposed between the ribs 5 and 6 is the base, or supportingportion, of a flexible scratcher element generally designated 12. Thescratcher element 12 preferably comprises a bundle or group ofindividual, relatively thin, wires 13, which are encased in a coilspring 14, but which project from the coiled spring at their free endsas at 15.

The scratcher element 12, about at its mid-point, is folded back uponitself so as to be generally U-shaped with its arms extending along therespective opposite sides of the stem 8 of the T-shaped member 7. At thepoints where the arms of the scratcher element 12 contact the T-head 9,the T-head 9 causes the scratcher element arms to flex outwardly so thatthey will project into engagement with the walls of a bore hole. Theaforesaid enlargement 10 on the T-head also constitutes a spacer betweenthe arms of the scratcher element 12 so as to maintain them in operativespaced relation. As is best shown in Figures 1 and 2, the scratcherelements 12 and their respective T-members 7 are preferably disposed atan angle with relation to the axis of the collar 1 and the pipe orcasing 4. g

' In order to firmly secure the T-shaped member 7 and the scratcher eement 12 in place between the ribs 5 and 6,the ribs 5 are preferablypunched inwardly or indented as at 17 into engagement with the stem 8 ofthe T-s aped member 7. which is preferably composed of a flexiblematerial such as rubber, neoprene, or the like,

Patented Jan. 17, 1961 so that the stem 8 will be more or lesscompressed as is clearly shown in Figure 3. Pressure on the stem 8 willdeform the flexible material and cause it to flow into the spaces atopposite sides of each rib 6 as at 18. In addition, the flexiblematerial of the stem 8 will bulge outwardly as at 19 into the spacebetween ribs 5. Thus the T-shaped element 7 is securely locked in place.

In order to aid in securing the scratcher element 12 in position. a tab20 is preferably punched or struck out of the collar and bent over thebase of the scratcher elernent 12 with the free end of the tab 20disposed within the arcuate end of the scratcher element 12 as is bestseen in Figure 3. During operation, the pipe or casing 4 will besubjected to vertical movement in the bore hole of a well, and the ends15 of the scratcher elements 12 will scratch the surface of the borehole to remove mud cake or other deposits therefrom. In order to enhancethe scratching action of the ends 15, the free ends of the Wires 13 arepreferably spread out to some extent so as to in effect pro ide crowsfeet at the ends of each of the scratcher elements 12.

During such scratching action, the arms of the scratcher elements may bedisplaced from the head 9 of the T-shaped member 7, but their naturaltendency is to assume their original position as illustrated. In orderto assist the arms of the scratchers 12 to re-assume their originalpositions, the opposite ends of the T-heads 9 are preferably bevelled sothat the scratcher element arms will cam up on the bevelled ends.

In addition, when the T-shaped element 7 are composed of a material suchas rubber, or neoprene, or the like, the pressure of the arms of thescratcher elements 12 upon the T-h'ead 9 will depress seats 21 in theouter faces of the T-head 9, these seats serving to partially retain theflexible arms in position during use of the scratcher. It should beunderstood, however, that if desired, the T-s'naped elements 7 may becomposed of material or materials other than resilient ones, but mosteffective locking of the T elements 7 in position may be etfected whenthe T elements are composed of resilient material. I

' In view of the foregoing, it will now be apparent that I have providedan improved wall scratcher device wherein the flexible scratcher fingersare firmly and easily secured in an operative position upon thesupporting collar without resorting to the use of screws or otherfasteners which might tend to break or loosen during use of thescratcher. Furthermore, the mounting means for the scratcher fingerseliminates any abrupt corners against which the flexible fingers may bebent and caused to break due to concentrated stress.

While the specific details of the invention have been herein shown anddescribed, changes and alterations may be resorted to without departingfrom the spirit thereof as definedin the appended claims.

I claim:

1. A wall scratcher of the class described adapted to be mounted on oilwell pipe or casing, comprising an annular collar, a plurality offlexible scratcher fingers having mounting portions and free scratchingportions, means securing said mounting portions on said collar with saidmounting portions lying along the side of said collar and extendinggenerally axially thereof and with said free portions projectingoutwardly from said collar and axially past an end thereof, saidsecuring means including a resilient member mounted on said collaradjacent the end of said collar past which said free scratching portionsproject and having a portion thereof underlying said scratcher fingersat the juncture of the mounting portions and free scratching portions ofsaid fingers and flexing the free scratching portions outwardly.

2. A Wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a plurality offlexible scratcher fingers having mounting portions and free scratchingportions,

means securing said mounting portions on said collar with said freeportions projecting outwardly from said collar, and a member underlyingsaid scratcher fingers and flexing the same outwardly, said securingmeans including a rib on said collar overlying the mounting portion ofeach scratcher finger, a rib on said collar underlying said mountingportion, and said member having a resiilent portion interposed betweensaid ribs, one of said ribs being crimped to compress said resilientportion towards the other rib.

3. A Wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, said scratcher element being generallyU-shaped and including a pair of scratching arms, said securing meansincluding a rib on said collar overlying said arms, and said memberunderlying the free portion of the scratcher element having a stemdisposed between said arms beneath said rib.

4. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, said scratcher element being generallyU-shaped and including a pair of scratching arms, 'said securing meansincluding a rib on said collar overlying said arms, and said memberunderlying the free portion of the scratcher element having a stemdisposed between said arms beneath said n'b, said rib being depressedinto engagement with said stem.

5. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and a.member underlying said free scratching portion and flexing the sameoutwardly from said collar, said scratcher element being generallyU-shaped and including a pair of scratching arms, said securing meansincluding a rib on said collar overlying said arms, and said memberunderlying the free portion of the scratcher element having a stemdisposed between said arms beneath said rib, said securing means alsoincluding a tab overlying the base of the U-shaped scratcher element.

6. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, said scratcher element being generallyU-shaped and including a pair of scratching arms, said securing meansincluding a rib on said collar overlying said arms, and said memberunderlying the free portions of the scratcher element being composed ofresilient material and having a stem disposed between said arms beneathsaid rib, said rib being depressed into engagement with said stem tocompress the same.

7. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, aflexible'scratcher element having a mounting portion and a 'freescratching portion, means securing said mounting portion on said collar,and a member underlying said free scratching portion and flexing thesame outwardly from said'collar, the member underlying said' freescratching portion being generally T-shaped and including a headdisposed laterally beheath the scratcher element and a stem co-extensivewith the scratcher element, said scratcher element comprising alongitudinally extended member folded back upon itself at the end ofsaid stem and providing a pair of "scratcher arms extended at oppositesides of said stem.

8. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, the member underlying said free scratchingportion being generally 'T-shaped and including a head disposedlaterally beneath the scratcher element and a stem co-extensive with thescratcher element, said scratcher element comprising a longitudinallyextended member folded back upon itself at the end of said stem andproviding a pair of scratcher arms extended at opposite sides of saidstem, and said securing means comprising a rib on said collar overlyingsaid scratcher arms and said stem.

9. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, aflexiblescratcher element having a mounting portion and a freescratching portion, means securing said mounting portion on said collar,and a member underlying said free scratching portion and flexing thesame outwardly from said collar, the member underlying said freescratching portion being general- 1y T-shaped and including a headdisposed laterally beneath the scratcher element and a stem co-extensivewith the scratcher element, said scratcher element comprising alongitudinally extended member folded back upon itself at the end ofsaid stem and providing a pair of scratcher arms extended at oppositesides of said stem, and said head having a projection thereon disposedbetween the scratcher arms for maintaining the latter in spacedrelation.

10. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, the member underlying said free scratchingportion being generally T-shaped and including a head disposed laterallybeneath the scratcher element and a stern co-extensive with thescratcher element, said scratcher element comprising a longitudinallyextended member folded back upon itself at the end of said stem andproviding a pair of scratcher arms extended at opposite sides of saidstem, and said head having bevelled ends for camming the scratcher armsback to a normal position upon displacement of the latter.

11. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, a flexiblescratcher element having a mounting portion and a free scratchingportion, means securing said mounting portion on said collar, and amember underlying said free scratching portion and flexing the sameoutwardly from said collar, wherein the member underlying said freescratching portion being generally T-shaped and including a headdisposed laterally beneath the scratcher element and a sternco-extensive with the scratcher element, said scratcher elementcomprising a longitudinally extended member folded back upon itself atthe end of said stem and providing a pair of scratcher arms extended atopposite sides of said stem, said T-shaped member being composed ofresilient material, and said securing means including a rib overlyingsaid scratcher arms and said stem, said rib being indented into theresilient material.

12. A wall scratcher of the class described adapted to be mounted on anoil well piping or casing, comprising an annular collar, said collarhaving a plurality of ribs forming a socket therebetween, a T-shapedmember having a stem disposed in said socket, flexible scratcher armsdisposed in said socket at opposite sides of said stem and projectingfrom said socket, said T- shaped member also having a head underlyingsaid scratcher arms for flexing said arms outwardly with relation tosaid collar, and means for retaining said T- shaped member and saidscratcher arms in said socket.

13. A wall scratcher of the class described adapted to be mounted on anoil well piping or casing, comprising an annular collar, said collarhaving a plurality of ribs forming a socket therebetween, a T-shapedmember having a stem disposed in said socket, flexible scratcher armsdisposed in said socket at opposite sides of said stem and projectingfrom said socket, said T-shaped member also having a head underlyingsaidscratcher'arms for flexing said arms outwardly with relation to saidcollar,one of said ribs being indented into engagement with the stem ofsaid T-shaped member for retaining said T-shaped member in said socket.

14. A wall scratcher of the class described adapted to be mounted on anoil well piping or casing, comprising an annular collar, said collarhaving a plurality of ribs forming a socket therebetween, a T-shapedmember having a stern disposed in said socket, flexible scratcher armsdisposed in said socket at opposite sides of said stem and projectingfrom said socket, said T-shaped member also having a head underlyingsaid scratcher arms for flexing said arms outwardly with relation tosaid collar, and a tab on said collar overlying said scratching arms forretaining the latter in said socket.

15. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing comprising an annular collar, said collar havinga plurality of ribs forming a socket therebetween, a resilient T-shapedmember having a stem disposed in said socket, a longitudinally extendedscratcher element folded back upon itself around the end of said stemand providing a pair of flexible scratcher arms projecting from saidsocket at opposite sides of said stem, said T-shaped member also havinga head underlying said scratcher arm for flexing said arms outwardlywith relation to said collar, and means for retaining said T-shapedmember and said scratcher member in said socket.

16. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing comprising an annular collar, said collar havinga plurality of ribs forming a socket therebetween, a resilient T-shapedmember having a stem disposed in said socket, a longitudinally extendedscratcher element folded back upon itself around the end of said. sternand providing a pair of flexible scratcher arms projecting from saidsocket at opposite sides of said stern, said T-shaped member also havinga head underlying said scratcher arm for flexing said arms outwardlywith relation to said collar, means for retaining said scratcher elementin said socket, and one of said ribs being indented towards another ofsaid ribs to compress the resilient T-shaped member there between.

17. A wall scratcher as defined in claim 16 wherein the means forretaining said scratcher element in said socket comprises a tab on saidcollar overlying the base of said scratcher element.

18. A wall scratcher of the class described adapted to be mounted on anoil well pipe or casing, comprising an annular collar, said collarhaving a pair of ribs punched outwardly therefrom, a resilient generallyT- shaped member having a stem disposed beneath said ribs, scratchingmeans composed of a longitudinally extended member folded back uponitself about the end of said stem and having a pair of scratcher armsdisposed beneath said ribs and extended along the opposite sides of saidstem, said ribs being indented into engagement with said T-shaped memberto compress the same, said Tshaned membe also h ving :a 'head di posedbe -w en said rscrat he a ms an said col a o flexin h scrat h armszutward y with msp ckt sa d l a and a t-tab punched outwardly; from saidcollar and overlying the ghase :Qf ;said ,scratcher element at the endof said stem- 19. A walliscratcherof the,clas s described adapted to bemounted on an ;oil well pipe or casing, comprising an annular collar, yaflexible scratcher element having a mounting portion and ,,,a freescratching portion projecting axially past an end of said collar, meanssecuring said mounting portion ,on saidcollar with said mounting portionlying alongthe ,side of said collar and extending axially thereof, andmeans on said collar including a projection adjacentthe end of-;saidcol1ar past which-said fingers project and disposed beneath said freeportion at the juncture of themounting portion and free scratchingportion for fiexing the free scratching portion out- ,yvar dly from saidcollar,;s aidsecuringmeans including a member integral.with; said collarand projecting outwardan ann ar a o ian a plurali :of flexi le cr hcr.elc-

-,m.nts disposed incircumferentially spaced relation about said collarand each having a mounting portion and a free scra ch g -;p.or.t .o p jin P n e :of said son r, me ns sc u insr aid mo n Portion n sai collarwith said mounting portion lying along the ;side of the collar andextendingaxiallythereof, and means .on= .said collar including aprojection beneath said fr ee scratching portion adjacent the end ofsaid collar past which said free scratching portion projectsandunderlying the respective scra tcher element at the juncture of themounting and free scratching portions thereof for flexing the freescratching portion outwardly from said collar, said securing meansincluding a rib on said collar overlying the mounting portion of therespective scratcher fingers, said rib being crimped into engagement.with

said mounting portion. 1

References Cited in the file of this patent UNITEDSTATES PATENTS1,309,587 Radinse July 8, 1919 2,634,813 Wright Apr. 14, 1953 2,687,178Atkinson Aug 24, 1954 2,713,9L2 Baker July 26, 1955 2,714,424 AtkinsonAug. 2, 1955 2,735,495 Hall Feb. ;21, 1956 FOREIGN PATENTS 523,850 GreatBritain July 24, 1940

